Communication system, base station apparatus, server apparatus, mobile station apparatus, and transmission data amount determining method

ABSTRACT

It is advantageous for present invention to suitably determine amounts of transmission data for links in a multilink communication. In a mobile communication system ( 10 ) for making a multilink communication through which a communication is performed by using a plurality of links relayed by a plurality of base station apparatus ( 30 ), respectively, each of the base station apparatuses ( 30 ) acquire transmittable data amount information representing amounts of data able to be transmitted through the respective links by a mobile station apparatus ( 20 ) or a server apparatus ( 40 ), and the mobile station apparatus ( 20 ) or the server apparatus ( 40 ) determines amounts of transmission data to be transmitted to the respective links in correspondence to the transmittable data amount information, and transmits communication data of amounts of data corresponding to the amounts of transmission data determined to the respective links.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/236,154,filed on Sep. 26, 2005, and claims the benefit of priority under 35 USC119 of Japanese application no. 2004-281927, filed on Sep. 28, 2004, andJapanese application no. 2005-190639, filed on Jun. 29, 2005, the entirecontents of all of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a communication system, base stationapparatus, a server apparatus, a mobile station apparatus, and atransmission data amount determining method.

In multilink communication through which communication is performed bysimultaneously using a, plurality of links (refer to Patent document 1for example), a communication apparatus needs to allocate data to betransmitted to each link. Heretofore, the communication apparatus formaking the multilink communication has monitored amounts of datareceived through the respective links (amounts of received data), andhas determined amounts of data to be transmitted through the respectivelinks (amounts of transmission data) in correspondence to the amounts ofreceived data. Thus, the communication apparatus allocates thetransmission data to the respective links based on the amounts oftransmission data thus determined.

-   [Patent document 1] JP 2002-94595 A

However, there is a difference between the reception communicationenvironment and the transmission communication environment in manycases. In the above-mentioned conventional method, the communicationapparatus has determined the amount of transmission data incorrespondence to the amounts of received data even in such cases.Hence, in a multilink communication system having a radio section, adifference has been caused between the amount of transmission data whichthe communication apparatus has determined and an amount oftransmittable data due to an influence of an error rate or a data ratein the radio section in some cases. As a result, delay or retransmissionof the data to be transmitted is caused. Thus, communication ceases asthe case may be.

SUMMARY OF THE INVENTION

In the light of the foregoing, it is, therefore, one of objects of thepresent invention to provide a communication system, base stationapparatus, a server apparatus, a mobile station apparatus, and atransmission data amount determining method which enable amounts oftransmission data for respective links to be suitably determined in amultilink communication.

In order to attain the above-mentioned object, according to an aspect ofthe present invention, there is provided a communication system formaking a multilink communication through which a communication isperformed by using a plurality of links, the communication systemincluding: transmittable data amount information acquiring means foracquiring transmittable data amount information representing amounts ofdata able to be transmitted through each of the links; transmission dataamount determining means for determining amounts of transmission data tobe transmitted to each of the links, in correspondence to thetransmittable data amount information; and communication datatransmitting means for transmitting communication data of amounts oftransmission data corresponding to the determined amounts oftransmission data to each of the links.

By adopting this constitution, the communication system can determinethe amounts of transmission data for each of the links in correspondenceto the amounts of transmittable data for each of the links constitutingthe multilink. That is, it becomes possible to suitably determine theamounts of transmission data for each of the links.

In addition, preferably, in the communication system, plurality of thecommunications are made in the communication system, and thetransmittable data amount information acquiring means acquires thetransmittable data amount information for each communication.

In this case, even when the plurality of communications are made, theamounts of transmission data for each of the links can be suitablydetermined every communication.

According to another aspect of the present invention, there is provideda communication system for making a multilink communication throughwhich a communication apparatus makes a communication by using aplurality of links, in which each of said links is a link through whichdata is relayed by each of a plurality of relay communicationapparatuses, each of the relay communication apparatuses includes:transmittable data amount information acquiring means for acquiringtransmittable data amount information representing an amount of datawhich said communication apparatus is able to transmit through the linkrelayed by the relay communication apparatus; and transmittable dataamount information transmitting means for transmitting the transmittabledata amount information to the communication apparatus, and thecommunication apparatus includes: transmittable data amount informationreceiving means for receiving the transmittable data amount informationtransmitted thereto; and communication data transmitting means fortransmitting communication data of amounts of transmission datacorresponding to amounts of transmittable data represented by thetransmittable data amount information to each of the links.

By adopting this constitution, the communication system can determinethe amounts of transmission data for each of the links in correspondenceto the amounts of transmittable data which is transmitted from the relaycommunication apparatuses of the respective links constituting themultilink. That is, the amounts of transmission data for the respectivelinks can be suitably determined in the multilink communication.

In addition, preferably, in the communication system according to theanother aspect of the present invention, the communication systemincludes a mobile communication system, the communication apparatuscommunicates with a mobile station apparatus included in the mobilecommunication system by using the plurality of links, the relaycommunication apparatus is base station apparatus included in the mobilecommunication system, and the transmittable data amount information isinformation representing amounts of data which can be transmitted fromthe base station apparatus to the mobile station apparatus.

In this case, the communication system can determine the amount of datato be transmitted from the communication apparatus in correspondence tothe amount of data which can be transmitted from the base stationapparatus to the mobile station apparatus every link.

In addition, preferably, in the communication system according to theanother aspect of the present invention, the transmittable data amountinformation may be determined in correspondence to the number ofcommunications in a radio section of the base station apparatus, thetransmittable data amount information may be determined incorrespondence to an error rate in a radio section of the base stationapparatus, or the transmittable data amount information may bedetermined in correspondence with a data rate in a radio section of thebase station apparatus.

Also, preferably, in the communication system according to the anotheraspect of the present invention, the communication apparatuscommunicates with a plurality of mobile station apparatuses while usinga plurality of links with respect to each of the mobile stationapparatuses, the transmittable data amount information receiving meansreceives transmittable data amount information from each of base stationapparatuses, respectively, every mobile station apparatus, with respectto each of the links used for the communication with the correspondingmobile station apparatus, the communication data transmitting meansincludes rate calculating means for calculating rates of amounts oftransmittable data for each of the links based on transmittable dataamount information received with respect to the each of links everymobile station apparatus, and the communication data transmitting meanstransmits the communication data to each of the links in correspondenceto the rates calculated by the rate calculating means, therebytransmitting communication data of amounts of transmission datacorresponding to amounts of transmittable data represented by thetransmittable data amount information to the links, respectively.

Moreover, preferably, in the communication system according to theanother aspect of the present invention, the communication systemincludes a mobile communication system, the communication apparatus is amobile station apparatus included in the mobile communication system,and the relay communication apparatus is base station apparatus includedin the mobile communication system.

In those cases, the communication system can determine the amount ofdata to be transmitted from the mobile station apparatus incorrespondence to the amount of data, which the mobile station apparatuscan transmit to the base station apparatus, every link.

According to still another aspect of the present invention, there isprovided base station apparatus for use in a mobile communication systemin which a mobile station apparatus communicates with a server apparatusby using a plurality of links relayed by a plurality of base stationapparatus, respectively, the base station apparatus including:transmittable data amount information acquiring means for acquiringtransmittable data amount information representing an amount of dataable to be transmitted through the link relayed by the base stationapparatus from the base station apparatus to the mobile stationapparatus; and transmittable data amount information transmitting meansfor transmitting the transmittable data amount information to the serverapparatus or the mobile station apparatus.

According to yet another aspect of the present invention, there isprovided a server apparatus for use in a mobile communication system inwhich a mobile station apparatus communicates with a server apparatus byusing a plurality of links relayed by a plurality of base stationapparatus, respectively, the server apparatus including: transmittabledata amount information acquiring means for acquiring transmittable dataamount information representing amounts of data able to be transmittedfrom each of the base station apparatuses to the mobile stationapparatus; and communication data transmitting means for transmittingcommunication data of amounts of transmission data corresponding toamounts of transmittable data represented by the transmittable dataamount information to each of links.

According to a further aspect of the present invention, there isprovided a mobile station apparatus for making a communication by usingat least one of a plurality of links relayed by a plurality of basestation apparatus, respectively, in a mobile communication systemincluding the plurality of base station apparatus, the mobile stationapparatus including: transmittable data amount information acquiringmeans for acquiring transmittable data amount information representingamounts of data which the mobile station apparatus is able to transmitthrough the links relayed by each of the base station apparatuses; andcommunication data transmitting means for transmitting communicationdata of amounts of transmission data corresponding to amounts oftransmittable data represented by the transmittable data amountinformation to each of links.

According to an even further aspect of the present invention, there isprovided a transmission data amount determining method of determining anamount of transmission data for each link in a communication system formaking a multilink communication through which a communication isperformed by using a plurality of links, the transmission data amountdetermining method including: a transmittable data amount informationacquisition step of acquiring transmittable data amount informationrepresenting amounts of data able to be transmitted through each of thelinks; a transmission data amount determination step of determiningamounts of transmission data to be transmitted to each of the links,respectively, in correspondence to the transmittable data amountinformation; and a data transmission step of transmitting transmissiondata of amounts of transmission data corresponding to the determinedamounts of transmission data to each of the links.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a construction of a mobilecommunication system according to an embodiment of the presentinvention;

FIG. 2 is a block diagram showing a configuration of a mobile stationapparatus according to the embodiment of the present invention;

FIG. 3 is a block diagram showing a configuration of base stationapparatus according to the embodiment of the present invention;

FIG. 4 is a block diagram showing a configuration of a server apparatusaccording to the embodiment of the present invention;

FIG. 5 is a functional block diagram showing configurations of theserver apparatus, and the base station apparatus according to the firstembodiment of the present invention;

FIG. 6 is a processing flow chart according to the first embodiment ofthe present invention;

FIG. 7 is a processing flow chart according to the first embodiment ofthe present invention;

FIG. 8 is a processing flow chart according to the first embodiment ofthe present invention;

FIG. 9 is a functional block diagram showing configurations of themobile station apparatus and the base station apparatus according to thesecond embodiment of the present invention; and

FIG. 10 is a processing flow chart according to the second embodiment ofthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The preferred embodiments of the present invention will hereinafter bedescribed in detail with reference to the accompanying drawings.

A mobile communication system 10 according to an embodiment of thepresent invention, as shown in FIG. 1, includes a mobile stationapparatus 20, a plurality of base station apparatus 30, and a serverapparatus 40. The mobile station apparatus 20 and the server apparatus40 are connected to each of base station apparatuses 30 throughcommunication paths (links).

A mobile station apparatus 20, as shown in FIG. 2, includes a controlportion 21, a storage portion 22, and a radio communication portion 23.The control portion 21 controls individual portions of the mobilestation apparatus 20, and executes processing relating to a call and adata communication. The storage portion 22 operates as a work memory ofthe control portion 21. In addition, the storage portion 22 holdstherein a program and parameters relating to various kinds of processingto be executed by the control portion 21, and stores therein a programas well relating to the present invention. The radio communicationportion 23 includes an antenna and a wave detector. The radiocommunication portion 23 modulates an audio signal, a packet for acommunication, and the like in accordance with an instruction inputtedthereto from the control portion 21 and outputs the resulting signalthrough the antenna. Also, the radio communication portion 23 receivesand demodulates an audio signal, a packet for a communication, and thelike which arrive at the antenna and outputs the resulting signal to thecontrol portion 21.

The radio communication portion 23 makes a communication bysimultaneously using a plurality of links for one communication, i.e.,through a plurality of base station apparatus 30 for one communication.When a plurality of links are used in such a manner, the control portion21 determines rates of amounts of data to be transmitted through therespective links.

The base station apparatus 30, as shown in FIG. 3, includes a controlportion 31, a storage portion 32, a radio communication portion 33, anda network interface portion 34. The control portion 31 controlsindividual portions of the base station apparatus 30 and executesprocessing relating to a call and a data communication. The storageportion 32 operates as a work memory of the control portion 31. Inaddition, the storage portion 32 holds therein a program and parametersrelating to various kinds of processing to be executed by the controlportion 31, and stores therein a program as well relating to the presentinvention. The radio communication portion 33 includes an antenna and awave detector. The radio communication portion 33 receives anddemodulates an audio signal, a packet for a communication, and the likefrom at least one mobile station apparatus 20, respectively, and outputsthe resulting signal to the control portion 31. The radio communicationportion 33 modulates an audio signal, a packet for a communication, andthe like which are inputted from the control portion 31 in accordancewith an instruction inputted thereto from the control portion 31, andoutputs the resulting signal through the antenna. The network interfaceportion 34 is connected to a communication network (not shown). Thenetwork interface portion 34 receives an audio signal, a packet for acommunication, and the like from the server apparatus 40 connected tothe communication network and outputs the audio signal, the packet for acommunication, and the like to the control portion 31. Also, the networkinterface portion 34 transmits the audio signal, the packet for acommunication, and the like to the server apparatus 40 in accordancewith an instruction issued from the control portion 31.

The base station apparatus 30 transmits a signal received from themobile station apparatus 20 to the server apparatus 40, and transmits asignal received from the server apparatus 40 to the mobile stationapparatus 20. In such a manner, the base station apparatus 30 serves asa relay communication apparatus for relaying a communication madebetween the mobile station apparatus 20 and the server apparatus 40.

The server apparatus 40, as shown in FIG. 4, includes a control portion41, a storage portion 42, and a communication portion 43. A computersuch as an exchange, a personal computer, a work station, or a mainframe is preferably used as the server apparatus 40. The control portion41 controls individual portions of the server apparatus 40 and executesprocessing relating to a data communication and various kinds ofinformation processing. In addition, the control portion 41 displays theresults of the processing on display means (not shown). The controlportion 41 receives an input signal from input means (not shown) andexecutes processing corresponding to the input signal. The storageportion 42 operates as a work memory of the control portion 41. Inaddition, the storage portion 42 holds therein a program and parametersrelating to various kinds of processing to be executed by the controlportion 41, and stores therein a program as well relating to the presentinvention. The communication portion 43 is connected to a communicationnetwork (not shown), and connected to a Plurality of base stationapparatus 30 through the communication network.

The communication portion 43 makes a communication by simultaneouslyusing a plurality of links for one communication, i.e., through aplurality of base station apparatus 30. When a plurality of links areused in such a manner, the control portion 41 determines rates ofamounts of data to be transmitted through the respective links.

As described above, the mobile station apparatus 20 and the serverapparatus 40 in this embodiment make one communication with each otherby simultaneously using a plurality of links. Incidentally, thecommunication system for making one communication by simultaneouslyusing a plurality of links in such a manner is called a multilinkcommunication.

In this embodiment, the base station apparatus 30 acquires informationon an amount of data (an amount of transmittable data) which the mobilestation apparatus 20 and the server apparatus 40 can transmit-especiallyin a radio section of the links which the base station apparatus 30relays, and informs the mobile station apparatus 20 or the serverapparatus 40 of the information on the amount of data. The mobilestation apparatus 20 or the server apparatus 40 distributes thetransmission data to the respective links in correspondence to theamounts of transmittable data. Hereinafter, a constitution andprocessing relating to the processing, for distributing the transmissiondata to the respective links, which is executed in the server apparatus40, and a constitution and processing relating to the processing, fordistributing the transmission data to the respective links, which isexecuted in the mobile station apparatus 20 will be described as thefirst embodiment and the second embodiment, respectively.

The First Embodiment

FIG. 5 is a functional block diagram showing configurations of the basestation apparatus 30 and the server 40 according to the first embodimentof the present invention. Referring to FIG. 5, the base stationapparatus 30 functionally includes a reception RF processing portion 50,a received data transmitting portion 51, a transmittable data amountcalculating portion 52, a transmission data receiving portion 53, and atransmission RF processing portion 54. In addition, the server apparatus40 functionally includes a received data receiving portion 60, atransmittable data amount acquiring portion 61, a distributioncontrolling portion 62, and a transmission data receiving portion 63.

The reception RF processing portion 50 receives, a radio signaltransmitted thereto from, each of the mobile station apparatuses 20.Then, the reception RF processing portion 50 demodulates the receivedradio signal to acquire communication data, and transmits thecommunication data to the received data transmission portion 51. Thereceived data transmission portion 51 transmits the inputtedcommunication data to the server apparatus 40 corresponding to the linksthrough which the mobile station apparatus 20 which has transmitted thatcommunication data makes a communication.

The transmittable data amount calculating portion 52 acquires radio bandinformation based on a radio signal (up radio signal), from each of themobile station apparatuses 20, which is received by the reception RFprocessing portion 50. The radio band information is informationrepresenting a degree of communication margin in a radio section. Morespecifically, the radio band information represents the number ofcommunications in the radio section, an error rate or a data rate in theradio section, etc. Next, the transmittable data amount calculatingportion 52 calculates the amount of transmittable data based on theacquired radio band information. The amount of transmittable data meansan amount of data (an amount of down transmittable data) which can betransmitted from the base station apparatus 30 to the mobile stationapparatus 20. The details of processing for calculating amounts oftransmittable data (processing for determining amounts of transmittabledata) will be described later. The transmittable data amount calculatingportion 52 outputs information on the amount of transmittable datacalculated to the received data transmitting portion 51. The receiveddata transmitting portion 51 transmits the inputted information on theamount of transmittable data to the server apparatus 40.

The received data receiving portion 60 receives the communication datatransmitted from the base station apparatus 30 and outputs thecommunication data as received data to a communication processingportion (not shown). The transmittable data amount acquiring portion 61acquires information on amounts of transmittable data contained in thecommunication data which is outputted to the communication processingportion by the received data receiving portion 60.

The distribution controlling portion 62 determined rates of distributionof the communication data to the respective links based on the amountsof transmittable data which the transmittable data amount acquiringportion 61 acquires. The distribution rates become criteria when thetransmission data transmitting portion 63 distributes the communicationdata to the respective links. That is, the transmission datatransmitting portion 63 transmits the communication data inputtedthereto from the communication processing portion (not shown) to therespective links at the distribution rates determined by thedistribution controlling portion 62.

The transmission data receiving portion 53 receives the communicationdata transmitted thereto in the manner as described above, and outputsthe communication data to the transmission RF processing portion 54. Thetransmission RF processing portion 54 transmits the inputtedcommunication data to the mobile station apparatus 20.

Hereinafter, a description will be given with respect to processing(processing for determining an amount of transmittable data) forcalculating an amount of data which can be transmitted from the serverapparatus 40 to the mobile station apparatus 20 through thecorresponding base station apparatus 30 by the transmittable data amountcalculating portion 52 in the mobile communication system 10 having sucha construction with reference to processing flow charts shown in FIGS. 6and 7.

FIG. 6 is a flow chart explaining processing for determining an amountof transmittable data in the corresponding base station apparatus 30. Inthe processing shown in the figure, when a plurality of mobile stationapparatuses 20 make the multilink communications with the serverapparatus 40 by using a plurality of base station apparatus 30 as therelay communication apparatuses, respectively, each of base stationapparatuses 30 pays attention to a communication which one mobilestation apparatus 20 makes, and makes the communication an object oftransmission data amount determining processing which will be executedfrom now on. Incidentally, each of base station apparatuses 30successively pays attention to communications which the mobile stationapparatuses 20 make, respectively, and executes the transmission dataamount determining processing for each of those communications.

As shown in FIG. 6, firstly, each of base station apparatuses 30acquires data on the number of users (the number of mobile stationapparatuses 20) who are making respective communications by using thesame frequency as that in a notable communication in the radio section(S100). “The number of mobile station apparatuses 20 each making acommunication by using the same frequency as that in the notablecommunication” is one of the above-mentioned radio band information.

Next, each of base station apparatuses 30 acquires data on a modulationclass in the notable communication (S102). For example, QPSK, 16QAM,etc. are known as the modulation class. When modulation is performedusing QPSK, each of base station apparatuses 30 acquires data on QPSK.“The modulation class in the notable communication” is also one of theradio band information, and is information representing the data rate inthe radio section.

Moreover, each of base station apparatuses 30 acquires a Frame ErrorRate (FER) predicted value in the notable communication (S104). “The FERpredicted value in the notable communication” is also one of the radioband information, and is information representing the error rate in theradio section. Hereinafter, processing for calculating an FER predictedvalue will be described in more detail with reference to FIG. 7. Itshould be noted that the processing for calculating an FER predictedvalue is executed in parallel with the transmittable data amountdetermining processing.

FIG. 7 is a flow chart explaining the processing for calculating an FERpredicted value in the base station apparatus 30. As shown in thefigure, each of base station apparatuses 30 calculates the FER in thenotable communication (S150), and stores the calculated FER in thestorage portion 32 (S152). Then, it is judged whether or not the numberof FERs, in the notable communication, stored through this processinghas reached a predetermined value (S154). When it is judged in S154 thatthe number of FERs has not yet reached the predetermined number, time isstarted to be measured (S156), and it is judged whether or not apredetermined time has elapsed (S158). When it is judged in S158 thatthe predetermined time has elapsed, the processing of S150 is started tobe executed again. On the other hand, when the number of FERs hasreached the predetermined value, processing for calculating the FERpredicted value from a change amount of FER is executed (S160). Morespecifically, a time vs. FER curve showing a tendency of a changecorresponding to a time of the FER is acquired by performinginterpolation based on the least squares method or the like. Also, theFER (FER predicted value) at a prediction object time is acquired byapplying the time of the prediction object time to that curve. Each ofthe base station apparatus 30 can acquire the FER predicted value in themanner as described above.

Next, each of base station apparatuses 30 calculates an amount of data(amount of down-transmittable data), which can be transmitted throughthe notable communication, with respect to the radio section utilizedthrough the notable communication based on at least one of the radioband information typified by “the number of mobile station apparatuses20 each making a communication by using the same frequency as that inthe notable communication”, “the modulation class in the notablecommunication”, and “the FER predicted value in the notablecommunication” which have all been acquired (S106). Hereinafter, thecalculation processing will be described in detail.

Incidentally, in the following calculation processing, the base stationapparatus 30 calculates the amount of transmittable data by applying theamount of transmittable data to any one of a plurality of stages (Sstages from a stage 1 to a stage S in this case). That is, the basestation apparatus 30 stores concrete values of the amounts oftransmittable data in correspondence to the respective stages. The basestation apparatus 30 firstly calculates the stage to which the amount oftransmittable data belongs, and uses the concrete value made correspondto the calculated stage as the amount of transmittable data.

Firstly, a description will be given with respect to a case where theamount of transmittable data is calculated based on “the number ofmobile station apparatuses 20 each making a communication by using thesame frequency as that in the notable communication” (S100 and S106).When n is assigned to “the number of mobile station apparatuses 20 eachmaking a communication by using the same frequency as that in thenotable communication”, the stage D to which the amount of transmittabledata belongs can be determined in correspondence to “the number ofmobile station apparatuses 20 each making a communication by using thesame frequency as that in the notable communication” from Expression 1.Here, a notation [ ] is a Gauss' notation. When n≦X<n+0.1, this notationrepresents that a decimal fraction of X is rounded down to zero so as toobtain [X]=n.D=[S/n]  (Expression 1)

Next, a description will be given with respect to a case where theamount of transmittable data is calculated based on “the modulationclass in the notable communication” (S102 and S106). When the data ratein “the modulation class in the notable communication” is assigned R andthe maximum data rate is assigned R_(max), the stage D to which theamount of transmittable data belongs can be determined in correspondenceto “the modulation class in the notable communication” from Expression2. The higher the data is, the more data can be transmitted. As aresult, the amount of data to be transmitted can be increased as thedata rate becomes higher.D=[S×R/R _(max)]  (Expression 2)

Next, a description will be given with respect to a case where theamount of transmittable data is calculated based on “the FER predictedvalue in the notable communication” (S104 and S106). When “the FERpredicted value in the notable communication” is assigned F, and themaximum FER at which the mobile station apparatus 20 can perform thedemodulation is assigned F_(max), the stage D to which the amount oftransmittable data belongs can be determined in correspondence with “theFER predicted value in the notable communication” from Expression 3. Thehigher the FER is, a less data is transmitted. In this case, however,the amount of data to be transmitted can be reduced as the FER becomeshigher.D=[S×(F _(max) −F)/F _(max)]  (Expression 3)

Finally, a description will be given with respect to a case where theamount of transmittable data is calculated based on all “the number ofmobile station apparatuses 20 each making a communication by using thesame frequency as that in the mobile communication”, “the modulationclass in the mobile communication”, and “the FER predicted value in themobile communication” (S100, S102, S104, and S106). The same notation asthat in the foregoing is used. In this case, the stage D to which theamount of transmittable data belongs can be determined from Expression4:D=[S/n×(R/R _(max))×(F _(max) −F)/F _(max)]  (Expression 4)

Each of the base station apparatus 30 compares the amount oftransmittable data calculated in the manner as described above with theamount of last transmittable data the information on which is stored inthe storage portion 32 prior to execution of processing of S112 (S108).When the comparison results show that a difference between the amount oftransmittable data calculated and the amount of last transmittable datadoes not fall within a predetermined value, each of base stationapparatuses 30 transmits transmittable data amount informationrepresenting the amount of transmittable data calculated to the serverapparatus 40 (S100). On the other hand, when the comparison results showthat the difference therebetween falls within the predetermined value,each of base station apparatuses 30 transmits no transmittable dataamount information. Only when it becomes clear through the comparisonprocessing that a change equal to or larger than the predetermined valueoccurs in the amount of transmittable data, the transmittable dataamount information can be transmitted to the server apparatus 40. Theinformation on the amount of transmittable data calculated is stored asinformation on the amount of last transmittable data in the storageportion 32 (S112). Incidentally, the transmittable data amountinformation representing the amount of transmittable data calculated maybe transmitted to the server apparatus 40 unless a difference betweenthe amount of transmittable data calculated and any one of a pluralityof amounts of last transmittable data the information on which is storedfalls within the predetermined value. As a result, even when the amountof transmittable data changes a little at a time, the information on theamount of transmittable data can be transmitted.

After the information on the amount of transmittable data is stored,time is started to be measured (S114). It is then judged whether or nota predetermined time has elapsed (S116). When so, the operation returnsback to the processing of S100, and the processing for calculating theamount of transmittable data is repeatedly executed again.

From the foregoing, the server apparatus 40 can acquire the amount oftransmittable data every communication and every link from each of basestation apparatuses 30. Next, a description will be given with respectto processing for determining the distribution rate based on the amountof transmittable data for each link by the distribution controllingportion 62.

FIG. 8 is a processing flow chart showing a part of transmissionprocessing when the server apparatus 40 transmits data to the mobilestation apparatus 20 by using a plurality of links. The distributioncontrolling portion 62 firstly selects a notable communication fromamong a plurality of communications being made by the server apparatus40 and acquires the links making communications (a plurality of links inan ordinary case) in the notable communication. The distributioncontrolling portion 62, with respect to the acquired links (the linknumber is expressed by n (n≧1)), receives transmittable data amountinformation (amount of transmittable data represented by thetransmittable data amount information is expressed by P_(n)) which istransmitted from the base station apparatus 30 through the acquiredlinks, and stores the transmittable data amount information in thestorage portion 42 (S200). After receiving the transmittable data amountinformation from all the base station apparatus 30 through the linksmaking communications in the notable communication, the distributioncontrolling portion 62 calculates a transmission rate (the distributionrate: expressed by R_(n)) for each link (S202). More specifically,preferably, the distribution rate is calculated from Expression 5:R _(n) =P _(n) /ΣP _(n)  (Expression 5)

where Σ represents a total sum about n.

The server apparatus 40 distributes the communication data on theamounts of data of the respective rates corresponding to thetransmission rates R_(n) thus calculated for the respective links to therespective links, and transmits the communication data through therespective links (S204). As a result, the transmission becomes possiblewith the amount of data corresponding to the amount of downtransmittable data for each communication and for each link.

Consequently, it becomes possible to suitably determine the amount oftransmission data every link in the multilink communication. Inaddition, even when a plurality of communications are made, it becomespossible to suitably determine the amounts of transmission data for therespective links every communication. In other words, the amount of datato be transmitted from the server apparatus can be determined everycommunication and every link in correspondence to the amount of data,for each link, able to be transmitted from the base station apparatus tothe mobile station apparatus, i.e., the amount of data able to betransmitted in the down radio section.

Second Embodiment

FIG. 9 is a functional block diagram showing configurations of themobile station apparatus 20 and the base station apparatus 30 accordingto the second embodiment of the present invention. Referring to FIG. 9,the base station apparatus 30 functionally includes a transmittable dataamount calculating portion 55 in addition to the reception RF processingportion 50 and the transmission RF processing portion 54. In addition,the mobile station apparatus 29 functionally includes a transmissioncontrolling portion 70, a transmission RF processing portion 71, areception RF processing portion 72, a transmittable data amountacquiring portion 73, and a distribution controlling portion 74.

The transmittable data amount calculating portion 55 acquires radio bandinformation based on a radio signal (up radio signal), from each of themobile station apparatuses 20, received by the reception RF processingportion 50. The radio band information is information representing adegree of communication margin in a radio section. Concretely speaking,the radio band information represents the number of communications inthe radio section, an error rate or a data rate in the radio section,etc. Next, the transmittable data amount calculating portion 55calculates an amount of transmittable data based on the acquired radioband information. The processing for calculating an amount oftransmittable data is similar in concrete contents to that executed inthe transmittable data amount calculating portion 52. However, theamount of transmittable data in this case means an amount of data(amount, of up transmittable data) which can be transmitted from themobile station apparatus 20 to the base station apparatus 30.

The transmittable data amount calculating portion 55 outputs informationon the amount of transmittable data calculated to the transmission RFprocessing portion 54. The transmission RF processing portion 54transmits the inputted information on the amount of transmittable datato the mobile station apparatus 20.

The reception RF processing portion 72 receives communication datatransmitted thereto from the base station apparatus 30 and outputs thereceived communication data as received data to a communicationprocessing portion (not shown). The transmittable data amount acquiringportion 73 acquires information on the amounts of transmittable datacontained in the communication data which is outputted to thecommunication processing portion (not shown) by the reception RFprocessing portion 72.

The distribution controlling portion 74 determines the rates ofdistribution of the communication data to the respective links based onthe amounts of transmittable data the information on which thetransmittable data amount acquiring portion 73 acquires. Thedistribution rates become criteria when the transmission controllingportion 70 distributes the communication data to the respective links.That is, the transmission controlling portion 70 determines the linksthrough which the communication data inputted from the communicationprocessing portion (not shown) is transmitted based on the distributionrates. The transmission controlling portion 70 make the communicationdata correspond to the respective links for transmitting thecommunication data, and outputs the transmission RF processing portion71. The transmission RF processing portion 71 transmits thecommunication data to the links which are made correspond to thecommunication data.

Hereinafter, a description will be given with respect to transmissionprocessing for transmitting the communication data based on the amountof transmittable data for each link in the mobile communication system10 having the construction as described above.

FIG. 10 is a processing flow chart showing a part of the transmissionprocessing when the mobile station apparatus 20 transmits the data tothe server apparatus 40 by using a plurality of links. As shown in thefigure, firstly, the mobile station apparatus 20 starts to make a datacommunication with the server apparatus 40 (S300). When the multilinkcommunication is intended to be made, more links are established (S301).The mobile station apparatus 20 implements multilink communicationthrough this processing.

Next, the mobile station apparatus 20 receives transmittable data amountinformation from a plurality of base station apparatus 30 which relaysthe respective links (S302). At this time, the mobile station apparatus20 stores information on the amount of transmittable data received fromeach of base station apparatuses 30. The mobile station apparatus 20judges whether or not there is a change in amount of transmittable datareceived from each of base station apparatuses 30 by comparing theamount of transmittable data the information on which is formerly storedand the amount of transmittable data the information on which isreceived with each other (S303).

When judging in S303 that there is no change in amount of transmittabledata, the mobile station apparatus 20 calculates the transmission ratesR_(n) for the respective links based on the received transmittable dataamount information (S304). This transmission rate calculating processingis the same as that in the first embodiment described above withreference to FIG. 8. The mobile station apparatus 20 instructs thetransmission controlling portion 70 to distribute and transmit thecommunication data the amount of which is the rates corresponding to thecalculated transmission rates R_(n) for the respective links to therespective links (S305).

On the other hand, when judging in S303 that there is a change in amountof transmittable data, the mobile station apparatus 20 judges whether ornot there is the link is generated which cannot be substantially used(S306). More specifically, the mobile station apparatus 20 judgeswhether or not there is a link where the amount of transmittable data issmaller than a predetermined value. Then, the mobile station apparatus20 judges that no data, can be substantially transmitted through thelink where the amount of transmittable data is smaller than thepredetermined value.

Next, the mobile station apparatus 20 judges whether or not there is thelink which can be substantially used (S307). More specifically, themobile station apparatus 20 judges whether or not there is the linkwhere the amount of transmittable data exceeds the predetermined value.When so, the mobile station apparatus 20 judges that there is the linkwhich can be substantially used. In this case, the mobile stationapparatus 20 abolishes the link which is judged to be unable to besubstantially used (S308). On the other hand, when the mobile stationapparatus 20 judges in S306 that no link is generated which cannot besubstantially used, and when the mobile station apparatus 20 judges inS307 that there is no link which cannot be substantially used, theoperation proceeds to the processing of S304 and the communication datais transmitted. The mobile station apparatus 20 repeatedly executes thiskind of processing until the communication is completed which hasstarted to be made in S300.

In this case as well, the mobile communication system can suitablydetermine the amount of up transmission data every link in the multilinkcommunication. In other words, the amount of data which is transmittedfrom the mobile station apparatus can be determined every link incorrespondence to the amount of data, for each link, which can betransmitted from the mobile station apparatus to the base stationapparatus, i.e., the amount of data which can be transmitted in the upradio section.

It should be noted that the present invention is not limited toEmbodiments 1 and 2 described above. For example, in Embodiments 1 and 2described above, the base station apparatus 30 calculates the amounts oftransmittable data. However, when the data on “the number of mobilestation apparatuses 20 each making a communication by using the samefrequency as that in the mobile communication” is not used, the mobilestation apparatus 20 can calculate the amounts of transmittable data. Ofcourse, if the data on “the number of mobile station apparatuses 20 eachmaking a communication by using the same frequency as that in the mobilecommunication” is transmitted from the base station apparatus 30 to themobile station apparatus 20, even when the data on “the number of mobilestation apparatuses 20 each making a communication by using the samefrequency as that in the mobile communication” is used, the mobilestation apparatus 20 can calculate the amounts of transmittable data.Likewise, when the information on transmittable data amount calculationbasic amounts such as “the number of mobile station apparatuses 20 eachmaking a communication by using the same frequency as that in the mobilecommunication”, “the modulation class in the notable communication”, and“the FER predicted value in the notable communication” transmitted fromthe base station apparatus 30 to the server apparatus 40 or the mobilestation apparatus 20, the amounts of transmittable data can becalculated in the server apparatus 40 or the mobile station apparatus 20as well.

In addition, while in Embodiments 1 and 2 described above, each of basestation apparatuses 30 acquires radio band information based on the upradio signal, each of base station apparatuses 30 may also acquire theradio band information based on the down radio signal. In particular,since in the first embodiment, the amounts of down transmittable dataare calculated, if the radio band information is acquired based on thedown radio signal, the amount of down transmittable data can be moreexactly calculated.

In addition, the present invention can be applied to not only the mobilecommunication system, but also all communication systems each of whichmakes a multilink communication.

While there have been described what are at present considered to bepreferred embodiments of the invention, it will be understood thatvarious modifications may be made thereto, and it is intended that theappended claims cover all such modifications as fall within the truespirit and scope of the invention.

Further, the disclosure of Japanese Patent Application Nos. 2004-281927filed on Sep. 28, 2004, and Japanese Patent Application Nos. 2005-190639filed on Jun. 29, 2005, including specification, claims, drawings andabstract is incorporated herein by reference in its entirety.

What is claimed is:
 1. A communication system for making a multilinkcommunication between a mobile station and a server by using a pluralityof parallel links, each of the links partially includes a radio link,said communication system comprising: transmittable data amountinformation acquiring means for acquiring transmittable data amountinformation representing amounts of data able to be transmitted throughthe radio link included in each of said links, based on radio bandinformation on the radio link; distribution rate determining means fordetermining rates of distribution of communication data to therespective links, based on amounts of transmittable data represented bythe transmittable data amount information relative to a sum of theamounts; and communication data transmitting means for transmittingcommunication data of amounts corresponding to the determined rates ofdistribution to each of said links.
 2. A server apparatus communicatingwith a mobile station apparatus by using a plurality of links relayed bya plurality of base station apparatus, respectively, wherein a partbetween each of the base station apparatuses and the mobile stationapparatuses in each of the links is a radio link, said server apparatuscomprising: transmittable data amount information acquiring means foracquiring transmittable data amount information representing amounts ofdata able to be transmitted through each radio link from each of saidbase station apparatuses to said mobile station apparatus; distributionrate determining means for determining rates of distribution ofcommunication data to the respective links, based on amounts oftransmittable data represented by the transmittable data amountinformation relative to a sum of the amounts; and communication datatransmitting means for transmitting communication data of amountscorresponding to the determined rates of distribution to each of saidlinks.
 3. A mobile station apparatus for making a communication to aserver by using a plurality of parallel links relayed by a plurality ofparallel base station apparatuses, respectively, wherein a part betweeneach of the base station apparatuses and the mobile station apparatus ineach of the links is a radio link, said mobile station apparatuscomprising: transmittable data amount information acquiring means foracquiring transmittable data amount information representing amounts ofdata able to be transmitted through each radio link from the mobilestation apparatus to each of said base station apparatuses; distributionrate determining means for determining rates of distribution ofcommunication data to the respective links, based on amounts oftransmittable data represented by the transmittable data amountinformation relative to a sum of the amounts; and communication datatransmitting means for transmitting communication data of amountscorresponding to the determined rates of distribution to each of saidlinks.
 4. A transmission data amount determining method of determiningan amount of transmission data for each link in a communication systemfor making a multilink communication between a mobile station and aserver by using a plurality of parallel links, each of the linkspartially includes a radio link, said transmission data amountdetermining method comprising: a transmittable data amount informationacquisition step of acquiring transmittable data amount informationrepresenting amounts of data able to be transmitted through the radiolink included in each of said links, based on radio band information onthe radio link; a distribution rate determination step of determiningrates of distribution of transmission data to the respective links,based on amounts of transmittable data represented by the transmittabledata amount information relative to a sum of the amounts; and a datatransmission step of transmitting transmission data of amountscorresponding to the determined rates of distribution to each of saidlinks.